//
// Function radioGroup() is a class to define an ARIA-enabled radiogroup widget.
//
// This widget attaches to an unordered list and makes each list entry a group
// of radio buttons.
//
// @param (id object) id is the html id of the <ul> to attach to
//
// @return N/A
//
function radioGroup(id) {

var thisObj = this;

///////// define widget properties ///////////////

this.$id = $('#' + id);

// find all list items with a role of radio
this.$buttons = this.$id.find('li').filter('[role=radio]');